Any
device which induces a pressure difference between two regions in
the system is called a pump. The pump which creates the vacuum in
the system is the Vacuum Pump.
There are two types of Vacuum pumps
1. Transfer vacuum pumps
2. Trapping vacuum pumps
Transfer
vacuum pumps are also known as kinetic pumps. They impart momentum
to the gas, which is pushed in such a way that the gas is transferred
continuously from the inlet of the pump to the outlet.
The
trapping vacuum pumps or the capture pumps are located inside the
containers being evacuated. They remove gas molecules by sorption
or condensation on its internal surfaces.
Vacuum
levels can be measured with simple manometer,i.e., U - tube. In general
the special devices which measure the vacuum levels are vacuum gauges.
Specifications
of vacuum pumps: